Ceilings - types
Ceilings are classified according to their appearance or construction. A cathedral ceiling is any tall ceiling area similar to those in a church. A dropped ceiling is one in which the finished surface is constructed anywhere from a few inches or centimetres to several feet or a few metres below the structure above it. This may be done for aesthetic purposes, such as achieving a desirable ceiling height; or practical purposes such as acoustic damping or providing a space for HVAC or piping. An inverse of this would be a raised floor. A concave or barrel-shaped ceiling is curved or rounded upward, usually for visual or acoustical value, while a coffered ceiling is divided into a grid of recessed square or octagonal panels, also called a "lacunar ceiling". A cove ceiling uses a curved plaster transition between wall and ceiling; it is named for cove molding, a molding with a concave curve.1 A stretched ceiling (or stretch ceiling) uses a number of individual panels using material such as PVC fixed to a permieter rail.
Źródło: https://en.wikipedia.org/wiki/Ceiling#Types
Molding - what is it?
Molding, or moulding (Commonwealth), also known as coving (UK, Australia), is a strip of material with various profiles used to cover transitions between surfaces or for decoration. It is traditionally made from solid milled wood or plaster, but may be made from plastic or reformed wood. In classical architecture and sculpture, the molding is often carved in marble or other stones.
A "sprung" molding has bevelled edges that allow mounting between two non-parallel planes (such as a wall and a ceiling), with an open space behind the molding. Other types of molding are referred to as "plain".
Źródło: https://en.wikipedia.org/wiki/Molding_(decorative)
What architectural elements we choose to make our interior look elegant?
In terms of internal stucco, there is really a wide range of products that will satisfy the most sophisticated tastes. Companies producing such products can be easily found via the Internet. The offer of these companies in the field of interior decorating usually refers to the production of elegant columns, moldings and rosettes. One must admit that the stucco interior architecture usually refer to past centuries and eras, and therefore would be expected to be quite classical elements that can be placed inside. A very popular feature stucco inside are strips that can emphasize the character of the place.